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Discussion Starter · #1 ·
Is there a way to test the fuel pump relay on the L-Jet cars?
 

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I think the main relay is a standard Bosch relay - with two #87 terminals. (some relays have 87 & 87a terminals)

Terminals #85 & #86 are the control terminals, when power is applied to those terminals it sends power from #30 to #87.

http://www.installdr.com/techdocs/999403.pdf
 

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Discussion Starter · #3 ·

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try this..is it quite were you are.. have a freind stand neer the open boot, turn ign. on/ for 3-5 sec. then off. repete, can you freind hear anything? no? then jump the relay plug at 30 to 87 this will make the fuel pump run, even by yourself if you have the rear cover off, with one hand reach and hold the big relay with your hand, and switch the car on, you should feel a ' click' of the relay..
 

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The fuel pump relay is energized 3 ways.

  • when the key is turned to on it energizes for just a moment to prime the fuel rail
  • when the key is turned to start, the relay is energized as long as the key is held in the start position
  • once the engine starts, the relay is kept energized by a tachymetric signal taken from the negative side of the coil

When you first turn the key to the on position, if you hear/feel the relay click, you should also hear the fuel pump(s) run for just a second.

Depending on your wingspan, from the passenger side of the car you may be able to hold the relay in one hand and reach over and turn the key with the other.

If this is so then the coil for the relay is good and the output contacts are good.

Turning the key to Start, (car in neutral, disconnect coil wire) the relay should click again and stay ON for the duration of cranking. During this time the fuel pumps should remain on until the key is released or the car starts. You probably won't be able to hear over the sound of cranking the engine so a test light or voltmeter will come in handy.

connect to terminals as noted below or connect to main fuel pump terminals

There should be 12v out of terminal 87. This is the line to the fuel pumps. Also 12v comes into the relay (to power the fuel pumps) on terminal 30. This line is fused right there by the relays and L-Jetronic controller. 8 amps, the original Alfa fuse holder is often not up to the task and can get warm enough to deform and lose contact. Jumping terminals 30 to 87 as Bianchi1 stated will demonstrate that the fuse, other wiring and fuel pump is good if this makes the fuel pump run.

There should also be 12v at terminal 15 of the Drive relay (fuel pump relay) when the key is turned to on.

There should be 12v at terminal 50 when the key is turned to start.
 

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There should be 12v out of terminal 50. This is the line to the fuel pumps.
Slight correction.
The output to the fuelpumps comes from fuelpump relay terminal #87.
Fuelpump relay terminal #50 is the input from the starter circuit.
 

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Discussion Starter · #7 ·
Jumping terminals 30 to 87 as Bianchi1 stated will demonstrate that the fuse, other wiring and fuel pump is good if this makes the fuel pump run.
Diagram shows a terminal #87 on both relays. Do I jump from #30 to #87 on same relay or over to the other relay?
 

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Jump them on the same relay. The 12v supply to the fuel pump relay (drive relay) is fused. More convenient and a bit safer too.


Papajam, thanks for catching that. I shouldn't type and think at the same time.
 

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Discussion Starter · #9 ·
The saga continues. Disconnected fuel line at rail and cranked but no fuel escaping even though pump is running while starter engaged (yes, there is fuel in the tank). I put an injector test lamp on the injector harness and I get very dim flashing light. Same test lamp on CSI produces bright light.

What are the symptoms if the in-tank pump is bad?
 

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How much fuel is in the tank?

If the in tank pump is bad the car will/should still run. The main pump doesn't pull well. It is designed to push. The in tank pump flows a steady stream of fuel past the main pump inlet. If the tank is full enough and hills, turns, spirited driving are avoided you may only notice some poor running, especially under the above circumstances.

If the stepped rubber hose is cracked or missing it will allow air into the system and the main pump will see no fuel


The CSI gets a steady 12v. It is either on or off. The main injectors get pulsed.
 

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Discussion Starter · #11 ·
How much fuel is in the tank?

If the in tank pump is bad the car will/should still run. The main pump doesn't pull well. It is designed to push. The in tank pump flows a steady stream of fuel past the main pump inlet. If the tank is full enough and hills, turns, spirited driving are avoided you may only notice some poor running, especially under the above circumstances.

If the stepped rubber hose is cracked or missing it will allow air into the system and the main pump will see no fuel


The CSI gets a steady 12v. It is either on or off. The main injectors get pulsed.
The tank is full - I didn't trust the gauge so I topped it off.

Are you referring to the corrugated intake hose from the AFM?
 

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what is referred to above is the small connection hose (with 2 different size openings, hence "stepped hose") joining the in-tank pusher pump to the fuel sender thingy!
IAP used to list it as # 17018 but cant see it listed anymore on their website?? forever gone?
a bit of creativity and you can make something up, just remember that any fuel hose submersed in petrol has to be submersible fuel line (like Gates make), normal fuel hose will slowly (or should I say quickly!) disintegrate on you..........
 

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Discussion Starter · #14 ·
Thanks for the pic. Pulling the assembly next.
 

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The fuel pump relay is energized 3 ways.

  • when the key is turned to on it energizes for just a moment to prime the fuel rail
  • when the key is turned to start, the relay is energized as long as the key is held in the start position
  • once the engine starts, the relay is kept energized by a tachymetric signal taken from the negative side of the coil

When you first turn the key to the on position, if you hear/feel the relay click, you should also hear the fuel pump(s) run for just a second.

Depending on your wingspan, from the passenger side of the car you may be able to hold the relay in one hand and reach over and turn the key with the other.

If this is so then the coil for the relay is good and the output contacts are good.

Turning the key to Start, (car in neutral, disconnect coil wire) the relay should click again and stay ON for the duration of cranking. During this time the fuel pumps should remain on until the key is released or the car starts. You probably won't be able to hear over the sound of cranking the engine so a test light or voltmeter will come in handy.

connect to terminals as noted below or connect to main fuel pump terminals

There should be 12v out of terminal 87. This is the line to the fuel pumps. Also 12v comes into the relay (to power the fuel pumps) on terminal 30. This line is fused right there by the relays and L-Jetronic controller. 8 amps, the original Alfa fuse holder is often not up to the task and can get warm enough to deform and lose contact. Jumping terminals 30 to 87 as Bianchi1 stated will demonstrate that the fuse, other wiring and fuel pump is good if this makes the fuel pump run.

There should also be 12v at terminal 15 of the Drive relay (fuel pump relay) when the key is turned to on.

There should be 12v at terminal 50 when the key is turned to start.
I will admit I did get a little confused about how to check these things..haha
I get 11.22v at terminal 15 when key turned to on but not cranking. I get about the same on terminal 50 with the key in the same position. When I turn the car over (cool wire disconnected), terminal 50 drops down to between 8v and 9v while cranking it over.
The fuel pump relay is energized 3 ways.

  • when the key is turned to on it energizes for just a moment to prime the fuel rail
  • when the key is turned to start, the relay is energized as long as the key is held in the start position
  • once the engine starts, the relay is kept energized by a tachymetric signal taken from the negative side of the coil

When you first turn the key to the on position, if you hear/feel the relay click, you should also hear the fuel pump(s) run for just a second.

Depending on your wingspan, from the passenger side of the car you may be able to hold the relay in one hand and reach over and turn the key with the other.

If this is so then the coil for the relay is good and the output contacts are good.

Turning the key to Start, (car in neutral, disconnect coil wire) the relay should click again and stay ON for the duration of cranking. During this time the fuel pumps should remain on until the key is released or the car starts. You probably won't be able to hear over the sound of cranking the engine so a test light or voltmeter will come in handy.

connect to terminals as noted below or connect to main fuel pump terminals

There should be 12v out of terminal 87. This is the line to the fuel pumps. Also 12v comes into the relay (to power the fuel pumps) on terminal 30. This line is fused right there by the relays and L-Jetronic controller. 8 amps, the original Alfa fuse holder is often not up to the task and can get warm enough to deform and lose contact. Jumping terminals 30 to 87 as Bianchi1 stated will demonstrate that the fuse, other wiring and fuel pump is good if this makes the fuel pump run.

There should also be 12v at terminal 15 of the Drive relay (fuel pump relay) when the key is turned to on or cranking it over.


There should be 12v at terminal 50 when the key is turned to start.
Thank you. When I hook up the multimeter positive to terminal 87 (larger fuel relay, not the smaller cube one) and ground the other l, I get no volts whether the key is in the on position or cranking it over.
I do get 12v at terminal 30
 

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The fuel pump relay is energized 3 ways.

  • when the key is turned to on it energizes for just a moment to prime the fuel rail
  • when the key is turned to start, the relay is energized as long as the key is held in the start position
  • once the engine starts, the relay is kept energized by a tachymetric signal taken from the negative side of the coil

When you first turn the key to the on position, if you hear/feel the relay click, you should also hear the fuel pump(s) run for just a second.

Depending on your wingspan, from the passenger side of the car you may be able to hold the relay in one hand and reach over and turn the key with the other.

If this is so then the coil for the relay is good and the output contacts are good.

Turning the key to Start, (car in neutral, disconnect coil wire) the relay should click again and stay ON for the duration of cranking. During this time the fuel pumps should remain on until the key is released or the car starts. You probably won't be able to hear over the sound of cranking the engine so a test light or voltmeter will come in handy.

connect to terminals as noted below or connect to main fuel pump terminals

There should be 12v out of terminal 87. This is the line to the fuel pumps. Also 12v comes into the relay (to power the fuel pumps) on terminal 30. This line is fused right there by the relays and L-Jetronic controller. 8 amps, the original Alfa fuse holder is often not up to the task and can get warm enough to deform and lose contact. Jumping terminals 30 to 87 as Bianchi1 stated will demonstrate that the fuse, other wiring and fuel pump is good if this makes the fuel pump run.

There should also be 12v at terminal 15 of the Drive relay (fuel pump relay) when the key is turned to on.

There should be 12v at terminal 50 when the key is turned to start.
I want to apologize. My phone is acting up. It sent my reply before I was done.
To recap:
I get no volts coming from terminal 87 on the larger fuel relay (not the small cube one), whether the key is in on position or cranking the car over.
I do get a little over 12v from terminal 30.
I get 11.14v on terminal 15 when the key is in on position but not cranking it over.
I get about 11.20v on terminal 50 when the key is turned to on position but not cranking. When I crank it over, terminal 50 drops down to a little over 9v.
Thoughts? Thank you.
 
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